There is an UPDATE ALL button you can click to update all the apps. But you still need to click the UPDATE button as each app comes up. But at least you don't have to go back to the Downloads screen each time. So it does save you a few steps.

However, I really would recommend against the UPDATE ALL button. Sometimes new releases add features that are not good (like ads!) that weren't in the old release. So I do take the time to read the latest comments to see if the new release introduced unwanted features or bugs that weren't in the old version.

You can select UPDATE ALL from the market if multiple updates are available, but that is only if the permissions for the individual apps have not changed. If the permissions on the update are different from the installed version, you must do it manually to approve those permissions.